1. Field of the Invention
This invention is concerned with milk sampling. The invention is more especially although not exclusively concerned with sampling milk in connection with the milking of animals, such as by an automated milking apparatus capable of milking animals without human supervision. There are known, for example, installations in which animals are free to visit a milking machine when they choose, and the milking machine is adapted to identify an animal visiting the machine and to decide if that animal is due to be milked. The automatic milking machine includes a robot arm for attaching teat cups to the teats of the animal if it is to be milked and a vacuum system to perform the actual milking. The milk extracted from the udder of the animal is conducted to a receiving vessel and, unless it is deemed of unacceptable quality for collection in which case it may be diverted and either discarded or collected for other use, the milk is subsequently delivered from the receiving vessel to a bulk storage tank in which the milk from an entire herd of animals may be accumulated and stored, the tank then being emptied once a day or every few days. For checking milk quality and for collecting data which can be helpful for herd management and for monitoring animal condition and state of health, it is usual for milk samples to be taken at the time of milking individual animals and subsequently analysed. Traditionally the samples from the respective animals are collected in small containers, such as sample tubes or the like, and the sample tubes with their contents are taken to a remote laboratory where an analysis of the milk samples is carried out. Sampling in this manner is generally performed regularly but only periodically such as once a month. In recent times analysers capable of analysing milk at or near to where the animals are milked have been developed and analysing equipment of this kind can have the advantage of the analysis results reaching the farm manager much quicker so that appropriate actions may be taken sooner to aid efficient milk production and the best possible animal welfare.
2. Description of the Related Art
In EP 1381269B there is described milk sampling and analysis of the latter kind. The milk analysing apparatus is arranged to analyse separately respective portions of a milk sample in order to provide, on a real time basis, quantitative measurements on a combination of compounds and parameters present in the milk samples from individual herd members or a group of herd members so as to derive from the samples data relating to the health condition, the physiological condition, the nutritional and energy state, the state of the oestrus cycle and pregnancy. Thus, the analysis can aid optimal utilisation of feed rations by implementation of feeding schemes on an individual animal or group basis, tight control of subclinical and clinical disease conditions that affect milk production and composition, optimal reproduction control and reliable pregnancy detection. Not every analysis is performed on every milk sample and a means is included for directing the milk sample portions to the separate analysing means only as desired, such as at pre-selected points of time, or pre-selected time intervals in the reproduction and/or lactation cycles. For obtaining the milk samples for analysis EP 1381269131 proposes automatic on-line collection at the milking site from the milking system and automatic transfer to the analytical means. The milking site may be the milking site of an automatic milking system for freely moving animals, or one of several milking sites in a more conventional milking system such as a herringbone milking system, or a rotating carousel type of milking parlour, or a parallel milking parlour. More specifically, for collecting milk samples from individual animals there is suggested in EP 1381269B1 a collecting means for collecting a proportional milk sample which is representative of the average composition of the total milk produced during the milking of each animal, and comprising a container for storing the sample, which container may be pressurised above the pressure of the milking system for subsequent and/or parallel transport of subsamples to the analysing means. Additionally the sample collecting means can comprise means for apportioning a milk sample to the analysing means, whereby a total sample is divided into one or more subsamples which is/are transported to the analysing means while a remaining part of the sample may be led to the bulk milk tank or discharged. While the milk collecting means is generally described in these terms in EP 1381269, no specific sample collecting arrangement adapted for use with an automatic milking machine is disclosed.
In EP 1267609 B1 there is described a milk sampling arrangement for use with an automated milking system and adapted to deliver milk samples to storage tubes for subsequent transport to a remote laboratory for analysis. The sampling arrangement includes a milk collection vessel into which a representative amount of milk, e.g. about 2% of the total amount of milk from an animal milking, is delivered from a conduit or vessel of the automated milking system. The collection vessel has two different discharge outlets at different heights, the upper outlet being connected to a discharge line and the lower outlet being at the bottom of the vessel and connected to one end of a hose having a filling member at the other end. The filling member is positionable over a selected sample tube by an X-Y positioning system. After all the milk to be collected from an animal milking has flowed into the vessel, compressed air is supplied to the vessel to stir the milk. The major part of the milk in the vessel is then discharged through the upper discharge outlet and may be thrown away, returned to the automated milking system or transported to the milk tank. A certain quantity of milk then remains in the lower part of the vessel and this milk sample is delivered through the lower discharge outlet to pass to the filling member and to the selected collection tube. The arrangement is suitable for collection of single milk samples in respective collection tubes.